If it is only 10 feet long, it could cost about $300. If it is 500 feet long the cost could be $6,000. And these prices could be a little high or a lot low depending on the conditions. But a steel pipe has a limited life. Domestic steel pipes can last 50 years or more, but imported pipes have failed in as little as 5 years. Without digging the pipe up, it is impossible to tell what its condition is and even then there may be no way to tell its potential remaining life. I would not pass on the house of your dreams if this is the only negative factor.: Hi,: We're considering buying an older house in Massachusetts. The inspector said the main water service pipe was very old, steel, and could need to be replaced at any time. He said this would be expensive, but he had no idea how much -- 5,000? 20,000? Any ideas? Should we pass on this house? Thanks